This invention relates generally to conveyor systems and, more specifically, to an article-transfer plate positioned to receive and transfer conveyed articles as they come off a conveyor section.
Conveyor belts or chains are used to transfer articles in many applications. In the beverage industry, for example, cans or bottles are transported through the plant on conveyor belts through manufacturing processes such as filling, pasteurizing, capping, labeling, and packaging. Until they are packaged, the individual bottles are transported in a stream along the belts. It is important that the bottles remain upright to prevent product from spilling and to prevent jams in the conveying line or at the processing stations. Because bottles are often top-heavy with relatively small bases, any discontinuity in the conveying path presents a tipping hazard.
Often it is necessary to transfer bottles from one conveyor belt to another. The gaps at transfer points between the two belts are typically filled with a deadplate across which the bottles are pushed by the backpressure of the steady stream of bottles on the upstream conveyor. The deadplate is positioned to minimize the size of the discontinuity between belts for smooth transfer. When the upstream conveyor is turned off or at the end of a manufacturing run, the last of the bottles can become stranded on the deadplate because there are no trailing bottles to push them along. Stranded bottles are frequently cleared by hand or by automated clearing systems similar to the bowling pin sweeper familiar to all. The manual clearing system requires manpower; automated systems, such as that described, are expensive and complex.
Thus, there is a need for a simple means to avoid stranding articles, such as bottles, at transfer points between conveyor sections in a conveyor system.
This need and others are solved by a novel article-transfer mechanism having features of the invention. The article-transfer mechanism includes a plate positioned between an upstream article feeder, such as conveyor belt, and a downstream article receiver, such as another conveyor belt or an article-accumulation area. The plate extends from a first end close to the upstream article feeder to a second end close to the downstream article receiver. The backpressure of a continuous stream of articles fed by the upstream article feeder pushes the articles onto the plate and across it to transfer the articles to the downstream article receiver. A vibrator coupled to the plate vibrates the plate to urge articles at the end of the stream from the first end toward the second end of the plate in the absence of backpressure. In this way, the article-transfer mechanism makes the plate self-clearing so that no articles are left stranded on the plate.
In another version of the article-transfer mechanism, the first end of the plate is disposed at a higher elevation than the second end of the plate to get an assist from gravity in urging the articles along the plate. A tilt of about 3xc2x0 off horizontal is preferred. In another version, the vibrator, which is preferably pneumatically driven, vibrates the plate in the direction of flow of the stream of articles between the first and second ends of the plate. In an alternative version, the vibrator vibrates the plate up and down. In yet another version, the vibrator is actuated only when the upstream article feeder is not feeding articles to the plate.
In another version of the invention, a conveyor system comprises a conveyor belt, a downstream article receiver, and an article-transfer mechanism disposed between the conveyor belt and the article receiver. The article-transfer mechanism includes a plate for receiving the stream of articles from the upstream conveyor belt and transferring the stream of articles to the downstream article receiver and a vibrator coupled to the plate to vibrate the plate. The vibration of the plate urges articles at the end of the stream across the plate and onto the downstream article receiver to avoid stranding articles on the plate.
Thus, the article-transfer mechanism of the invention eliminates the stranding of articles on a deadplate between conveyor sections.